Drying apparatus



Oct. 16 1923. 1,470,919

H. HAAS DRYING APPARATUS Filed Dec. 21, 12m 3 Sheets-Sheet 1 Fig.1, v 8

lnvenTor. Hermann Haas byiamd DRYI NG APPARATUS Filed Dec. 21, 1921 3 Sheets-Sheet 5 Fig.6..

\nvenTor. Hermann Hucls ATT S.

OCO

I Pented perms erransrus.

Application filed December 21, 1921. Serial it'o. 523,928.

T 0 (LE whom it may concern:

citizen of the Republic of Germany, and

resident of Lennep, Rheinland, Germany,-

have invented an Improvement in Drying Apparatus, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing'like parts.

This inventlon relates to drying apparatus of. that type which includes a drying tunnel or canal adapted'to receive a plurality of cars each carrying material to be dried, said cars being so arranged that when they are in the tunnel they divide the latter into separate sections. One of the objects of the invention is to provide an improved drying apparatus of this type which is constructed so that the drying current will be not only circulated repeatedly through each of the sections into which the tunnel is divided but will also be progressivelyadvanced from one section to another. In carrying out the invention'I arrange a plurality of heating chambers ateach side of the tunnel, there being one heating chamber on each side of the tunnel for each section thereof, and each heating chamber communicates at its upper end with the top of the tunnel section and at its lower end with the bottom of the tunnel section. Each heating chamber contains heating devices and a fan is provided at the top of each heating chamber which operates to draw air from the tunnel section into the top of the heating chamber and force the air through the heating chamber where it is heated, said air being delivered to the tunnel section at the bottom.

In order to provide the desired supply of air progressively I arrange the heating chambers at one side of the tunnel in an overlapping relation with regard to the tunnel sections so that while each of said heating chambers takes air from the top of its tunnel section it will deliver the heated air partly to the bottom of said section and partly to the bottom of the next adjacentsection. A portion of the air received in each tunnel section, therefore, is taken from the preceding tunnel section and the air constituting the drying current is thus circulated repeatedly through each section and at the same time progressively advanced from section to section. r

In order togive an understanding of the invention I have illustrated in the drawin s a selected embodiment thereof which Wlll now be described after which the novel features will be pointed out in the appended claims.

Fig.1 is a diagrammatic cross-sectional view through a drying tunnel embodyingmy invention.

Figs. 2, 3, 4 and 5 are plan views showing more or less diagrammatically the overlapping arrangement of heating chambers for difierent lengths of tunnels.

Fig; 6 is a view showing another embodiment ofthe invention.

In the drawings the drying tunnel, which may be of desired length, is indicated at K, said tunnel having any suitable construction and being adapted to receive a'plurality of cars 3 on which is supported the material to be dried. The material may be arranged on the cars on hurdles or sus ended thereon in any approved way depen ing on the character of the material. The separate cars are so arranged and constructed that when they are introduced into thetunnel they operate to divide the tunnels into sections,-

each section corresponding to the length of a car. These section are indicated at A, B, C, D and E in the drawings.

Situated on each side of the drying tunnel are a plurality of heating chambers, there being one heating chamber at each side of the tunnel for each section as formed by the cars. The heating chambers on one side of the tunnel are indicated at R, R R R", R and those on the other side by H H, H H*, H. Each heating chamber contains heating means indicated at 4 and each heating chamber communicates at its upper end with the top of the tunnel as shown at 6 and at its lower end with the bottom'of the tunnel as shown at 7. V indicates ventilating fans which are situated at the upper end of each heatin chamber and operate to draw air from t e corresponding tunnel sections and force it down through the heating chamber where itis delivered to the tun: nel sections through the air spaces 7 as shown by the arrows Fig. 1.

If each heating chamber corresponded exactly in position to each tunnel section then there would be a closed circulation through each heating chamber and its tunnel section. In order to provide for progressive advance of air through the various sections and, therefore, asupply of a certain proportion of unused air continuously to the tunnel I have arranged the heating chambers on one side of the tunnel with an overlapping relation in regard to the tunnel sections. For in stance the heating chamber H is arranged so that it overlaps slightly the tunnel section B and the heating chamber" H sothat it overlaps slightly the tunnel section C, the heating chamber H similarly being arranged to overlap the tunnel section D, etc. \Viththis arrangement the air whlch is withdrawn from the tunnel section A for instance will be carried down through the heating chamber H and because the heating chamber H overlaps somewhat the tunnel section B a portion of the air which passes down through the heating chamber H will be .delivered to the tunnel section B. The exact proportion of air which is thusdelivered depends upon the extent to which the heating chamber H overlaps the tunnel section B. Similarly a portion of the air withdrawn from the tunnel section B will be delivered to the tunnel section C and a portion of the air which is withdrawn from the tunnel section C will be delivered to the tunnel section D, and so on. There will, therefore, be a progressive advance of the heating current through the tunnel.

The amount of the overlapping will depend upon circumstances. In the case of ashort tunnel, as shown in Fig. 2, a relatively small degree of overlapping is sufficient. This is indicated by the space X Fig. 2. In the case of a 'longer tunnel such as shown in Fig. 3 the amount of overlapping will be greater as indicated at X For still longer tunnels the amount of overlapping will be still greater as shown at X and X in Figs. 4 and 5. With the longer tunnel, therefore, a greater amount of air is continually supplied to each section than with the shorter tunnel.

In manydrying apparatus of this type it is customary to provide means for causing the material to be dried to move through the tunnel in a direction counter to that in which the air current moves. For instance in the illustration the air current would enter at the left hand end of the tunnel and gradually' pass therethrough toward the right and the cars with the Wet material to be dried would be introduced into the right hand end of the tunnel. As the drying operation is carried on the cars are gradually advanced through the tunnel with a step by step movement. In such case if the material to be dried has an excessive moisture then it would be desirable to arrange the overlapping relation of the heating chambers so that the heating chambers at the right hand end where the material is wettest would have a ater overlapping relation than at the le t hand Where the material is driest as shown in Fig. 6. This is because a greater quantity of added air would be required in the portions of the tunnel containing the wettest material. If the material is very wet and the amount of air thus delivered is not sufficient a certain additional amount of air may be introduced by opening air inlets as shown at 8 which are located in the top 9 of the tunnel on the suction side of the ventilating fans at B. The extent of the heating surface in the heating chambers can be arranged to suit the requirements of use.

I claim.

1. A drying apparatus comprising a drying canal or tunnel adapted to receive one or more cars containing material to be dried and which are arranged to divide the tunnel into sections, a plurality of heating chambers on both sides of the tunnel, there being one chamber at each side for each section. each heating chamber communicating with the corresponding section at its top and bottom, means to cause a circulation through each heating chamber and the corresponding tunnel section, the heating chambers on one side of the tunnel having an overlapping relation to the tunnel sections whereby a portion of the air which is withdrawn from each tunnel section is delivered to the next adjacent tunnel section.

2. A drying apparatus such as described in claim 1 in which the cars with the mate rial to be dried are introduced into the tunnel at one end and are delivered with the dried material at the other end, the arrangement by which the overlapping of the heating chambersis greater at one end of the tunnel into which the wet material is intro duced.-

In testimony whereof, I have signed my name to this specification.

H. HAAS. 

